A company has m manufacturing facilities. The facility at the ith location has capacity to produce bi units of an item. The product should be shipped to n distribution centers. The distribution center at the jth location requires at least aj units of the item to satisfy demand. The cost of shipping an item from the ith plant to the jth distribution center is cij. Formulate a minimum-cost transportation system to meet each of the distribution center’s demands without exceeding the capacity of any manufacturing facility